And A Whole Lot of Running
by Ace of Gallifrey
Summary: The Doctor realizes that someone's been doing his job for him, someone who is quickly becoming an intergalactic legend. When he catches up to his imitator, he finds the last person he ever expected… ON HIATUS.
1. Prologue

**Title-** And a Whole Lot of Running  
**Characters/Pairings-** 10th Doctor, Donna, Jenny, no particular shippings  
**Summary-** The Doctor realizes that someone's been doing his job for him, someone who is quickly becoming an intergalactic legend. When he catches up to his imitator, he finds the last person he ever expected…  
**Notes-** First off, you need to disregard everything that happened from "Turn Left" onward. Just assume that Davros and the Daleks accidentally blew themselves up and it's all okay. This is MY universe, bitches! =P  
Secondly, and **most importantly**, I'm far from an expert in all things Gallifreyan (but let's face it: is anybody?). I've done as much research as I can (thank you Wikipedia!), and I'm relatively certain that I've got my facts in order. However, if there's some glaringly obvious problem… let me know, alright?

* * *

Prologue

A third tremor ripped through the core of the planet, this time creating deep fissures in the core's steel outer shell. Molten iron oozed outward slowly into the surrounding water. At such depths, at such pressures, robbed of the option of boiling, the water did the impossible- it burst into flames. The planet was synthetic, just a bubble of water held in place by the gravity field created by the factory-built metal core. Someone, however, had other ideas. The core was being ripped apart by a series of earthquakes generated by a transmitter located somewhere down here…

"It's just through there!" Kyo gurgled, swishing uncomfortably in the viciously hot water. He indicated a small service gap in the core's surface with his claw-like flipper.

The woman with him nodded, signaling with a thumbs up that she understood. Her blonde hair was tied up in a ponytail behind her head, and her blue eyes were concealed behind watertight goggles. A tank of compressed air was strapped to her back. "Thank you, Kyo," she said, voice muffled by her breathing apparatus. "Now, you need to get out of here."

"But-"

"You need to go." Her eyes were steely and her tone allowed for no options. Reluctantly, the aquatic gentleman swam away from the core.

The woman, meanwhile, was trying to slip in through the service gap. Her air tank, however, seemed to have other ideas. _Damn fortieth-century technology_, she griped inwardly. The tank was just… too big.

Another quake rocked the planet, and more fire leaked out from the core. She could feel gravity weakening as the structure's integrity became more and more compromised. The water was still held in place, but not for much longer…

She took a deep breath, then discarded the tank, ripping the mouthpiece out. It fell away from her, settling gently against the steel beneath her feet. Without wasting another moment, she dove through the narrow space. Inside, she found a series of equally tight passages, fanning out from her like a labyrinth. She had a dozen different choices, leading to dozens of other choices. The transmitter was tiny, possibly only a few centimeters in diameter. A technology scan would be the easiest way to find it... But she didn't have the equipment. There was no time. The planet would lose all integrity, gravity going slack and leaving the underwater denizens to drift into the vacuum of space within minutes.

Damn it.

Only one option, then. She closed her eyes, focusing, listening…

There. The beeping. The transmitter.

She ran-swam through the flooded steel corridors, feeling her lungs tightening as the minutes lengthened and she began to fear that she might have taken a wrong turn. Her lungs, strong though they were and of unusually large capacity even for her species, were beginning to burn from lack of oxygen. She wasn't lightheaded yet, but she would be soon, and that was bad. She needed all her wits about her to deactivate the transmitter. She was running out of time. Ironic, really.

When she arrived at a fork in the passages, she realized she had gotten turned around, but there was a potential shortcut, just there... She squeezed through the narrowest gap yet, silently thanking good Gallifreyan genes for her slight build.

The water around her was heating up. She would have estimated it was nearing 93 degrees, by human measurements, and at any second now, it would reach boiling point. Or, under these kinds of pressures, flaming point. Her body could take huge amount of abuse, but she wasn't sure she could survive that kind of damage.

But there, at last, was the transmitter. It was just a tiny round little button suctioned onto the wall; as she had guessed, it was only an inch across at the very most.

_Such a little thing_, she thought, _to cause so many problems._

With a quick flick of her wrist, she pried the front panel off the device and studied the delicate wiring inside. She immediately realized that she had absolutely no _clue_ how to deactivate it. Maybe two minutes before she passed out from oxygen deprivation. This was bad. Had she finally gotten herself in over her head?

_Probably not_, she decided.

And then she proceeded to seize a handful of wires and rip them out at random. When all else fails, just figure that inflicting as much damage as possible will shut anything down. She just hoped that there was no safety backup…

* * *

**A/N-** Just a short prologue, but future chapters will be longer. Updates will be somewhat regular, because although I don't have much of this written, I've drawn up a full outline and know exactly where this story is headed, beginning, middle, and end. I've even got a few vague ideas about a sequel, if this is well-received.  
I'm not going to be one of those authors who demands reviews before updating; however, I will stipulate that I will be more motivated to actually put my plan into action and write a little more regularly than I otherwise would have if I get more reviews. I'll update without them, but I think we all know that they help.


	2. 1: Whispers Across The Stars

**A/N-** Has anybody else noticed that the Doctor/Donna banter is extremely hard to write? I love Donna. She's my favorite of 10's companions; nevertheless, her own particular brand of sarcasm is hard to write. The Doctor- particularly Tennant's Doctor- is a challenge to begin with, but throwing Donna in the mix? Just about impossible!

* * *

Chapter 1: Whispers Across the Stars

"Where are we going?" Donna asked, clinging to the railing. "Do you have any particular destination in mind, or are you just dropping us somewhere random again? Because you know how that worked out last time-"

The Doctor grinned over his shoulder at her as he dashed around, flipping switches and spinning things and trying (unsuccessfully) to keep the TARDIS flying level and smooth. "Oh, Donna, I always have a _reason_," he defended. "I don't always know what the reason is, but there always is one."

"So you say," she said dubiously as a particularly rough lurch of the TARDIS nearly sent her sprawling.

A few more levers thrown about, and the usual chaos settled down into the familiar noise of a (relatively) smooth landing. "There you go!" the Doctor said. "Safe and sound."

"Alright then, where are we?" Donna said. She marched to the doors and pulled one open, only to be immediately deluged in a torrent of water slamming into her from without. With a cry of surprise, she struggled to shut the door against the rushing pressure of the water. The Doctor immediately ran to her aid and together, with a great deal of effort, they managed to slam the door closed- though not without getting soaking wet and introducing the lower levels of the TARDIS to rather more aquatic situations than she was used to.

"Right, forgot to tell you," the Doctor said, panting. He ran a hand through his hair, flinging beads of water everywhere. "We've landed in the planet Olsglsh."

"Don't you mean 'on?'" Donna corrected.

"No, I mean _in_. It's composed entirely of water except for the small steel-and-iron core, designed to produce enough of a gravity field to hold the water in a spherical shape," the Doctor corrected.

Donna rolled her eyes. "Just brilliant," she muttered. "And I suppose you couldn't have warned me before I went and opened the door?" When the Doctor failed to come up with a suitable response, she shook her head. "Alright, come on, let's put on something dry- and preferably something water-tight- and go out there."

Both safely ensconced in wet-suits, Donna and the Doctor exited the TARDIS, this time with the benefit of an air corridor to prevent the ship from being flooded again.

"But… won't the TARDIS drift away?" Donna asked. "If it's a water planet, surely there's tides and things?"

The Doctor just pointed, and she noticed the slender chain descending from the bottom of the TARDIS into the abyss below.

"Right," Donna said, nodding.

The Doctor then settled into the water, leaving the small bubble of air surrounding the doors of the TARDIS behind. Donna followed quickly.

"So what exactly are we doing here?" she asked, looking around them. Taking in the sight of the clear green water around them, shimmering with light from some unseen sun, and flickering occasionally with little silver flashes that she assumed were the result of some reflective native species, she smiled, but she was picking up on the Doctor's preoccupation. "I mean, it's gorgeous, but you just said yourself that you always have a reason for the places you go."

The Doctor glanced at her and there was a slight trace of worry on his face. Just the tiniest hint. Someone less attuned to him than Donna wouldn't have even noticed it. "The TARDIS picked up a distress signal coming from Olglsh sometime around… eh, last night, I suppose. I thought we'd come take a look."

Donna nodded. "Well, come on then! Stop dilly-dallying and let's get down to it." She glanced around. "Where exactly do the people live here?"

"Floating cities," the Doctor explained. "They're platforms that just sort of drift with the current. Very smart. Very ecologically-minded. And, unless I've misplaced a decimal point, very close." He turned around a few times, before his eyes caught on a dull gleam in the middle distance. "Ah, yes!" he exclaimed, a bright grin on his face. "There you are. Right over there. Come on, Donna!" Without a second's hesitation, he plowed away through the water.

Donna plucked irritably at the material of her wet-suit, then followed.

* * *

Donna stared around her as they strode through the streets of the Olsglshian city, which the Doctor had informed her a few minutes before was called Sshraap. It was magnificent, all organic structures and sea glass, spiraling and intertwining in a fantastic maze of glittering life. She could understand why it was considered to be one of the most popular intergalactic tourist destinations. Even the familiar sound of the Doctor sonicking a door open couldn't distract her from her overwhelmed staring.

He tugged on her arm. "Come on, Donna!" he hissed, pulling her inside.

She gaped at him. "How can you come to places like this and then go to Earth and be pleased with it?"

The Doctor shrugged. "It's not the Earth. It's the people."

Before he could say more, a voice interrupted. "I say, who are you?" a gurgling voice demanded.

The Doctor turned on his heel- the smooth motion made rather less smooth and a great deal less graceful by the water resistance- and faced the strange life-form approaching them. Vaguely humanoid in shape, the native of Olsglsh had a thick tail in place of legs, and the ends of his stubby arms trailed away into fanlike flippers. Most of his body was covered with scales, and he gazed at them with beady, unblinking eyes.

"Oh, hello," the Doctor replied jovially.

"What are you doing in the capitol reef? Who are you?" the man- or at least, probably a man, as Olsglshian gender could be difficult to determine at times- asked again.

"I'm the Doctor, this is Donna. We're here to speak to someone in charge- your grand vizier or someone."

At the mention of their names, the Olsglshian's green-gold eyes widened. "Doctor?" he asked softly.

"That's me," the Doctor said with a grin, rocking back on his heels (again, the movement didn't work so well underwater).

"It is an honor to have you return to Olsglsh," the fish-man said. "I am called Soi."

The Doctor shook his head, smile widening. "Oh, now, I said I'd be back, didn't I?"

Soi made an odd shrugging gesture. "It is an honor," he repeated. Then he flapped his fins in a brusque manner. "Follow me, then," he said. "It would be my pleasure to escort you to the vizier's chamber." With no further ado, he swam down the corridor. The Doctor and his companion followed at a little distance.

Donna shot her friend a glance, complete with raised eyebrow and knowing smirk. "'I said I'd be back?'" she quoted. "You've been here before?"

He shrugged. "I get around."

"So I can see. What did you do? He was practically falling all over himself when he found out who you were!"

"Oh, just a bit of trouble with an invasive species of carnivorous space-oysters... nothing major."

Donna snorted. "Right. Come on then, this Soi bloke is gonna leave us behind if we don't keep up!"

* * *

Soi showed them through to a chamber composed entirely of a blue glass dome; the sunlight sent a racket of rainbows cascading across the floor. "The Doctor and his companion," Soi announced before withdrawing. The chamber door shut behind them, and from across the room, another aquatic dweller approached them, trailing emerald fins.

"Greetings, Doctor," the newcomer said. "It has been far too long since you have visited."

"Not for me, it hasn't," the Doctor said, grinning. "Good to see you again, Kyo. Donna, may I introduce Kyo-Shin, grand vizier of Sshraap, capitol city of Olsglsh. Kyo, my good friend Donna Noble." The Olsglshian nodded politely and Donna waved cheekily.

"If I may inquire," Kyo asked, "What exactly has brought you back to Olsglsh? You rarely travel anywhere without a reason, Doctor."

The Doctor's face was suddenly just a little less jovial. "My ship detected a distress signal sent out from your planet late last night, Kyo. But I get here, and everything's perfectly in order... except the water's warmer. What's going on?"

Unexpectedly, Kyo chuckled, letting a stream of bubbles from his gills. "Oh, that," he said. "There was a spot of trouble yesterday, I will admit. We have had some unrest in the east, as you know. Political dissenters, anarchists, it is the same in any other system you like. In any case, a group of the fiends infiltrated the core and planted an antigravity device inside. Some ridiculous attempt to destroy Olsglsh, I suppose, though what good it would have done them I have no idea."

"Are you serious?" the Doctor asked, aghast both at the information and the cavalier attitude with which his acquaintance was presenting it.

"Quite," Kyo replied.

"How on earth...?"

"Did we thwart them?" the Olsglshian finished. "To be honest, Doctor, we didn't. _She_ did."

The Doctor blinked. "'She' who?"

"That is just it," Kyo said. "No one actually knows. She never gives her name, just calls herself the Lieutenant. Bit of an odd little thing, if I am honest. However, she is quite good at what she does, so eccentricities can be forgiven."

"And what, exactly, does this... _Lieutenant_... do?" the Doctor asked suspiciously. Donna could practically hear his brain working, trying to process all the information.

"In all honesty, Doctor, she is rather like you. The Lieutenant is becoming something of a galactic legend. She pops up every so often in trouble spots, does something complicated no one else understands to stop whatever has gone wrong, then disappears for years at a time only to appear somewhere else."

The Doctor looked deeply concerned at that. "Right," he said slowly, nodding. "So... she deactivated the antigravity transmitter?"

"That is the extent of it, yes. It was looking rather grim before the Lieutenant showed up, you see. Our people, as you know, are extremely sensitive to changes in temperature. The destabilization of the core allowed a great deal of molten iron to seep into the water. None of our people could get close enough without being roasted. The Lieutenant, though..." Kyo's bug-eyed face relaxed into an approximation of a beatific smile. "She strode right into the heart of the fire with no fear."

"Right..." the Doctor said, sounding distracted, looking around. "I... Well, thank you, Kyo. It was good to see you, but I think Donna and I need to be going. Some very important things to get back to, if you lot aren't in any trouble..."

"Very well," Kyo said, inclining the upper half of his body in something like a bow. "Well met, good Doctor, Miss Noble. Until you return."

The Doctor waved a vague goodbye and strode out of the chamber quickly, Donna practically tripping over herself in her haste to follow him. "Hey!" she shouted after him. "Wait up! Some of us do actually have water resistance! Not everyone is as skinny as your alien self!"

He slowed his pace, but didn't stop and didn't speak, apparently deep in thought. Several minutes later, when they had returned to the TARDIS and removed their wet-suits, the Doctor was still silent.

"What was all that, then?" Donna demanded. "The Lieutenant? What's that about, anyway? Sounds like a poor excuse for a Doctor copycat."

"That's what I'm afraid of," the Doctor murmured.

Picking up on the fact that it wasn't a laughing matter, Donna placed a concerned hand on his arm. "Doctor?" she asked softly.

"People think it's fun, what I do."

"Well, it is!" Donna protested.

"Yes, most of the time, but it's also incredibly dangerous- you know that as well as anyone. If it were just someone acting as a sort of galactic vigilante, that would be one thing. But that bit about disappearing for years at a time... that stinks of time travel. If someone with access to even some kind of minimal time travel device decided to try playing at being a Time Lord... Well, paradoxes are far too easy to create, and they tend to have disastrous consequences. There's a reason these things are best left up to those who have time sensitivity."

Donna bit her lip. "Then... what do we do?"

"We look for a vortex energy signature outside the TARDIS' footprint," he said, rushing suddenly to the console and began spinning dials as quickly as he could move. "If it's really someone time traveling, there'll be traces left behind, and we should be able to..." He leapt around to the monitor, and his face fell. "Oh dear," he said.

"What is it? Is it someone time traveling?" Donna asked.

"Yep," the Doctor said solemnly, pointing to the monitor. "Look here. This trace... about a mile down was its departure point... it's... I've never seen an energy signature like this. It's... it's..." He removed his spectacles, staring at the screen in amazement. "It runs on huon energy, like the TARDIS, you can tell from the radiation decay patterns, see? But however it works, it doesn't convert it the way the TARDIS does. This isn't Time Lord technology, that's for sure... but it's the closest approximation I've ever seen..."

Donna, as usual, really wasn't sure what he'd said except for the last bit. "Right, then, so what do we do?"

"We follow it," the Doctor said, head snapping around to look at her. He wore the delighted grin that so often decorated his face whenever he'd done something brilliant. "I can lock onto this energy signature and the TARDIS can follow it to the source..." He threw a switch, and the good ship hummed to life.

Donna put a restraining hand on the railing running around the console, suspecting that this particular trip was going to be a bit rougher than usual...

* * *

**Next time: Another planet, another time, another mystery. Same old, same old...**


	3. 2: Ipsilion

**A/N-** Sorry that this kind of turned into the Chapter of Donna Complaining. I was feeling strapped for dialogue, and in Donna's defense, she has had a bit of a rough journey over the last few TARDIS-days. Donna is my absolute favorite, but for some reason, in this chapter she came across as a whiner, and I'm not fond of it. That's a large part of why it has taken me so long to get this update out. I wanted to get it just right. Unfortunately, it looks like "just right" just isn't going to happen this time around, so I said "screw it" and posted after all.

* * *

Chapter 2: Ipsilion

Donna stumbled out of the TARDIS, swearing loudly as she weaved across the pavement. She had been right- it _had_ been a rough trip. And not just one, either. At least two dozen jumps across galaxies, always just a few steps behind the mystery woman they were tailing, and every one of them had been a near-disaster of a landing. Whatever kind of time-travel this woman was using, it was making the TARDIS _very_ upset!

"Blimey," the Doctor said, following her through the doors and waving a hand ineffectually through the smoke billowing after him. "Old girl hasn't been that upset since she accidentally crashed into herself! We'd better give her a rest for a few hours."

Donna nodded her agreement, peering through the door to survey the damage. It wasn't as bad as the smoke would seem to indicate- the TARDIS seemed to enjoy pyrotechnics a little too much for her own good, and frequently made minor damage look more... _theatrical_.

That didn't mean, of course, that she didn't plan on giving this Lieutenant a what-for once they finally tracked her down. It had been quite a merry chase thus far, and the stories they had come across on each world on which they landed were wild. A planet whose sun had been set to explode prematurely, rescued with the help of a simple gravitic anomalyzer. A political struggle on Raxicoricofallapatorius, solved by an unknown woman who had unmasked a traitor just in time. A space station with failed engines, repaired in minutes by someone the crew described as an "absolute mechanical wizard." A tiny human colony living on a massive asteroid, plagued by carnivorous worms and unable to send a distress signal, rescued by a woman who held the worms at bay with a homemade flamethrower until the evacuation was complete.

And those were just the first handful they came across! Some of the places the trail led them had no fantastic stories to tell; sometimes there were just strange people and beautiful worlds and lonely footprints in the dust, but for the most part, there was a continually growing list of worlds and people sitting safely in the sky, and trying to remember all of them was making Donna's head hurt.

Yes, a merry chase indeed. If the Lieutenant, whoever she was, kept this up, there wouldn't be much work left for the Doctor!

"So then, where are we now?" Donna asked, surveying the place in which they stood. A green-tinted sky arched above them, and a vast landscape of vaulting scarlet and gold rocks that glittered vibrantly stretched in every direction around them, sparsely populated with low-growing plants. The air around them shimmered ever so slightly as if with a mirage, though it wasn't particularly warm. The sunlight was unusually bright, but the heat wasn't anywhere near unbearable.

He glanced around briefly, and his face brightened considerably as he took in the landscape. "We're on Ipsilion!" he exclaimed. "Oh, this is brilliant! I haven't been here in _years_! Mind you, last time I was here there was a nasty bit of trouble with people turning green and losing their digits... but that was ages ago, literally. All sorted now. Gorgeous planet, anyway. Desert, mostly, and so beautiful it puts the red rocks of the Sonoran to shame! It's actually pretty well known in this sector of the galaxy, because the star it orbits emits low-spectrum radiation known as Corval radiation. Deadly if you're exposed to it outside the atmosphere- anything not properly shielded becomes molecularly unstable and dissolves- but Ipsilion's upper atmosphere is composed mostly of a phosphoric compound that binds with the radioactive particles and neutralizes them. It makes the compound heavier than the oxygen-rich lower layers of the atmosphere and the particles filter down to the surface of the planet. Mostly it ends up forming that crystalline layer you can see on the rocks there, all sparkly-like, but most carbon-based life forms can absorb it through the skin and metabolize it. Kind of like how your lot uses solar energy from your sun to produce vitamin D, but with the Corval radiation, it works to promote rapid cellular growth, to stimulate healing. People from all over the galaxy come here as a kind of... I guess you'd call it a day spa crossed with an oxygen bar crossed with a physical therapy centre. Brilliant, really."

"God, man, take a breath!" Donna said, making her best play at irritability, but she knew- and she knew the Doctor also knew- that she was just teasing him. "So, Ipsilion, then? Is this where the trail ends, or have we still got another dozen planets, two rockets and a black hole to go through before we catch up to this... this... whoever-she-is?"

The Doctor grimaced, throwing a glance at the still-vaporous TARDIS. "No, this is as far as I've been able to trace the energy signature."

"So... I suppose we'd best go take in the sights, hadn't we?" Donna said. "We're not gonna find anything just standing around here! Middle of nowhere, that's where we are! Which way to civilization, Doctor?"

"At my best guess, if we've landed where I think we have, is due east," the Doctor said, pointing toward a horizon mostly obscured by a large obelisk of carnelian stone. "There should be a leisure spa about a mile past that rock."

Donna grimaced. She loved traveling with the Doctor, but was it really too much to ask for once- just once- to be able to get where they were going without having to trek long distances under less-than-ideal conditions? "Come on, then," she said, feeling grateful for the straw-brimmed hat she just happened to have brought from home.

* * *

"How in the world can you possibly still have the energy to whistle?" Donna asked crossly. "It's boiling!" And it was. The temperature had steadily increased as the sun climbed higher in the sky.

"It's 'cause I'm not wearing a great big floppy hat!" the Doctor replied cheerily. Then his expression became briefly contemplative. "Mind you, I used to. Big old floppy brown hat... Can't for the life of me think what I've done with that..." Then he shook his head, snapping back to the present. "You're not getting any sun on your skin, Donna! It's rejuvenating, even to an old bloke like me. Give it a go for a few minutes without the hat; I think you'll see the difference."

Before she could protest, the Doctor's thin fingers whipped out and snatched the hat from her head, bathing her pale face in sunshine. She opened her mouth to protest...

And suddenly closed it again, as a rush of energy swept through her. It was a difficult feeling to describe, like a flash of slow-burning heat beneath her skin, but rather than making the already warm climate unbearable, she felt cooled and refreshed by it instead.

"Oh," she said.

The Doctor grinned brightly. "Corval radiation!" he exclaimed. "Come on, then!"

The rest of the trip went much more quickly, with Donna easily keeping up with the Doctor, and within half an hour the pair had reached a sparkling city of crystal and steel. As they stood at the top of a ridge, gazing up at the shining metropolis, Donna's breath caught.

"It's beautiful," she said softly, awe in her voice. No matter how many gorgeous worlds she saw during her travels with the Doctor, she was continually surprised by how much beauty the universe could produce in the most unexpected places.

She glanced at the Doctor, and saw that he had a wistful little smile on his face as he surveyed the city. "It is, at that," he agreed. "Very beautiful."

He looked over at her and the small smile turned into a full-blown grin as their eyes met. She couldn't help but grin back. "Alright then, let's go on in," she said, gesturing to the city across the plain.

* * *

Next Time: Ipsilion seems like paradise, but the Doctor quickly realizes that there's something very wrong, and he's not the only one...


End file.
